Quick search of facts after Laird/TMZ episode says surfing during your period is OK to do
Surfersvillage Global Surf News, 25 May, 2017 - When gossip site TMZ, hot on the story of rising shark sightings in Southern California, ambushed Laird Hamilton in a Malibu parking lot the legendary waterman was asked “What are the odds of being bitten? A lot of people are kind of worried (about sharks).”
In a video that's now become famous Hamilton, looking caught off guard, rambled off an answer about shark attacks not being fatal, then said it’s usually a case of mistaken identity. Then he dropped the bomb that lit up the internet.
“The biggest, the most common reason to be bitten is a woman with her period, which people don’t even think about that,” a disheveled Hamilton told the reporter. “Obviously if a woman has her period, there’s a certain amount of blood in the water.”
We did a little research to find out if surfing during your period can attract sharks. First off, the amount of blood is minimal and much less compared to the average scrape or cut.
“The amount of blood that is produced during menstruation (about 2 ounces over the entire cycle) is so small that it becomes background with all of the other components that are in the water,” says Dr. Chris Lowe, head of California State University, Long Beach’s Shark Lab told Outside Magazine in a 2012 article. “It would be very difficult for a shark to localize that.”
Last year a Dr. Steve Kajiura from Florida Atlantic University’s Shark Lab said there was no evidence that sharks attack those who are menstruating more than other people. Another reason sighted agianst Laird’s short-scienced comment is that tampons work pretty well at preventing leaking, yes, even while surfing.